Mechanical pencil



Sept. 24, 1929. J. c, WAH-l.

MECHANICAL PENCIL Filed Sept. 26, 1925 IIIII.

'10 mechanism after a lead has be Parental Sept. 24,19g9

PATENT?) OFFICE l .JonN C. wAHI., o1` CHICAGO, I'LmNoIs, AssIGNon To THEWAHI. CoatrANY, opwin- 4 armaron-DELAWARE, A ConronA'rIoN oF 1:n r.mrrAr ua| MECHANICAL PENCIL Application iue'a september 2e, 1923. serialNq. 664,896..

My invention relates to mechanical pencils and has for its. primaryobject the provision of an automatic pencil Whosel lead propellingmechanism is such that when all or substantially all ofthe lead in thefeed tube'is AeX-4 hausted through the tip, the said lead-propel# lingmechanism may lbe Withdrawn by directlongitudinal pull, thusveliminating the time wasting process of unscrewing the propelling enexhausted from thetip. l

Anotherobject of'm'y invention resides in providing anarrangement forpermitting the lead propelling mechanism .to be withdrawn v from thebarrel by a direct' longitudinal pull only at a positionwhen the leadpropelling mechanism has reached its limit in the lead propellinldirection of movement.

-Still a rther feature oftheinventi'on re- .sideszin the novelarrangement oflead'holding` chamberwhich is constructed and arranged sothat the leads can be lWithdrawn yWithout removing -them endwise fromthe barrel after unscrewing'the end cap as here- 25.tofore.

' In the drawings Fig. 1 is a longitudinal sectional view of finvention, showing the feeding mechanism in position, and the-erossheadin its uppermost 39 position in the chamber.

Fig. 2 is a longitudinal sectlonal View showing the interiormechansmofthe pencil, par tially sectionallyand partially fragment-ally,

With the lead propelling mecl1anism, consist 3,; ing of the 'crossheadandthe plunger at'the 'lower-most extremity..

Fig. 3 is alongitudinal sectional Wien",

mentally.

Fig. 4 is a. cross .sectional view of line' 4 4 sfinge.' f

Fig. 5 isa perspective View of the interior mechanism of the pncil. Fig.6 is a'per'spectiv'e viewof Aof the interior mechanism, to-:beafterwards.

specifically described. v Fig. 7 is a-crosssectional ofFig..1.

The Ad'ilicultyin the past Withthe Everpartially' sectionally'clandpartially' fraga..v portion 'view if line '7- -7 f sharp 'stylev ofmechanical pencils has been theslow and tedious loading process.` It wasnecessary after the exhaustion vofa lead from the -ti'p to unscrew themechanism lfrom .the

barrel which necessitated the turning of the cap 'some 23 completerotations to withdraw the Asaid mechanism from the ',barrel, thenunsereiv the cap lead cl1amber,removing a lead, and the screwv om thetop of the reserve, I

.ing-of the cap back on the top'of the reserve ,l

lead chamber.

The user next inserted the lead inthe end of the lead feedingmechanism,pushed the lead feedingmechanism into the barrel, turningd the cap in aclockwise direction until the crossh'ead in-the lead feeding 'mechanismengaged the threads-in the barrel and 'propelled the. lead through thetip. This processconsumes 'q uite some-time and three'quarters of thistime is eliminated inthe structure h Ynreinafter l to'be described.

1 The numeral 1 indicates an outer sheath -a lead holding member, Thelshell 2 has a thread -3' rolled therein-extending from' a shortdistance. aboye the shoulders'formed 'or `barrel,r`swedged at one 'end'forming a by the swedged en d'2a to a distance' about midway oppositeend o f the said tube.

Near theupper end 'of the tube 2 i'sjformd fa bead 4'w'hic`h cooperateswith thebead' rolled in the upper end ofthe barreltto pre'- Vvent Vthe-tube 2rom being inserted too j'far into the'barrel 1. The lowerswedged endl ofv v Athe'tube 2 is threaded as at 6 to receivefemalethreads onthe interior of the shank of the-'internally ribbed vsteel:tip 7 commonly calleda riied tip. It is not deemed vnecessary todescribe this rilled 'steel tip in detail except that itis that patentedby Chas. R.4

= Keeran, No. 1,151,016', August24, 1915.

-The tube 2 is-inserted in the barreluntil the bead 4 strikes bead 5j.'-The steel tip 7 is'scre'wed on to' thefeed tube' 6 which pro# jectsthrough the aperture in the swedged end j betweenithe. said shoulderandthe thus locking the tube 2 in the barrel and preventing rotationthereof.

The lead feeding unit or mechanism consists of an actuator or tube 8swedged at its lowermost end as at 9 to form an opening a little largerthan the diameter of a writing lead and slotted as at 10. The slot isformed by splitting the shell and turning the edges of the'split whichform guide flanges for a crosshead that is adapted to ride in the saidslotlO. This slot 10 extends from a position adja`cent to the shoulder11 formed by the swedging of the lower end 9 to a distance substantiallythe opposite end of the tube 8. A rectangular shaped aperture 11l ispunched in the said shoulder 11, the said aperture being puncheddirectlycb'elow and in alignment with the slot 10. y

The upper end of the tube 8 is threaded to receive an eraser holdingmember 12. Mounted in the actuator or tube 8 and extending through therectangular shaped aperture 11 is a U shaped guide sleeve or channelmember 13. This guide member has its flanges cut away for a portion oftheir length as at 14 to form retaining shoulders, and its end isbeveled as at 15, for a purpose hereinafter made evident.

The bottom of the U-shaped guide or channel member 13 is provided withan opening or slot 16. This slot has an exact location relative to thebeveled end 15 of the channel member as will be hereinafter madeevident. In addition, the .channel member is provided with a punched indetent or dimple 13 preferably located on one of the inner upstandingflanges. This dimple 13 is located a short distance to theI rear of theslot 16.

The slotted channel member constitutes one .embodiment of means to eausethe release of the crosshead 17 from threaded engagement with thethreads 3 of the inner tube 2 ofthe casing so as to permit thecrosshead, its plunger and the actuator tube 8 to be withdrawn bodilyrearwardly from the casing or barrel 1 by a direct rearward pull withoutthe laborious unscrewing as heretofore.

This guide member 13 is adapted to be inserted into the tube 8 throughthe uppermost endthereof and is confined between a washer 27 hereinafterdescribed and the lower conical shoulder 11 of the actuator tube 8ePreferably' the beveled end 15 of this guide member 13 projects into theslot 11 in the shoulder 11 of the tube 8 to prevent the channel memberfrom'rotating within and relatively to the tube 8, that is, from beingrotated within the tube and about its central amsA during the screwingof the actuator tube 8 bv reason of the fact that the crossheadrests inthe channel member and the tube and is in threaded engagement with androtatable relatively to the barrel 1. Since the crosshead thus projectsinto the Walls of the slot 10 in midway between said shoulder and' bemanifest that if thereof,

the actuator it must turn with the actuator. As thus held fromrotational movement, the bottom of the member 13 constitutes a guidewayfor one edge of the crosshead while theand threads onthe tube untilautomatically.

released by the registration of the slot 16 and a correspondinvly shapedadjacent portion of the crosshea A crosshead 17, having lateralprojections l 18 and 19, isprovided. This crosshead is threaded on oneedge as at 20, and on the op 1- posite edge is smooth as at 30, and of asize to pass into the slot 16 of the channel member 13. Fitted in anaperture in the lower 'edge of said crosshead, and projecting therefromis a plunger 21. The slot 10 in the tube 8 is spread and the plunger andcrosshead are inserted therein, the feed wire being pushed through theswedged end 9.

The smooth edge 30 of the crosshead 17 is inserted between the flangesof the member 13. In this position the threads on the opposite edgeproject through the slot 10. The slot 10 is then squeezed together andthe flanges therein slipped over the shoulders formed by the projections18 and 19 on the crosshead, and thus the crosshead and plunger are heldin position in the tube 8, having free longitudinal movement with norotary movement therein. As stated heretofore, the position of thecrosshead inside the tube is such that the threads 20 proj ect beyondthe peripheral edges of the slot 10 toengage the threads 3 of theinnerWall of the tube 2.

The tube 8 has a longitudinally extending slot 22 stamped therein at itsupper end.

Reverting now to the function of the slotted channel member 13 as ameans for permitting i disengagement of the crosshead 1'? from theadedengagement with the tube 2 it must the channel member were immobileendwise in the actuator tube 8 or if for instance the slot 16 wereformed directly in the wall of the actuator at the desired spacedrelation from the conical shoulder 11 the crosshead 17 would always befree to drop into this recess whenever the crosshead was positionedopposite this local tion of the slot. For instance, if the actuator werewithdrawn from its position shown in Figure 1 to that position shown inFigure 3, wherein the crosshead is still in threaded engagement with thethreads 3 of the tube 2, then if the slot 16 werein itsl same positionshown in Figure 1, the crosshead would register with slot 16 and woulddisengage from the barrel 1 at this point. This is objectionable.Therefore, to provide an arrangement wherein the crosshead will releasefrom threaded engagement with the barrel only at the extreme advancedposition of the cross i head and actuator within the barrel, whichslot16 out of'registration wit Gil corresponds to the exhaustedcondition of the lead in the tip, the slot 16 is formed in the 'channelor guide member- 13 and the latter l 5 is constructed and arranged toshift in the actuator tube -to automatically v between the washer 27 andthe conical shoulder 11 of actuator tube 8 so that the guide member canslide endwise therein. And since the beveled nose 15 of the guide member13 projects through the slot 11` of the shoulder 11, the guide member isfree to shift endwise in this direction until the shoulders 14 thereoncontact with the wallsy of the slot 11". In this position the channelmember will be in extreme forward position with the Vbeveled nose 15projecting soi'ne distance through the Y, slot 11Il asv illustrated inFigures 3 and 5.

This shifted position carries the slot 16 soA farv forwardly toward theconical shoulder 11 that it is out of registration with any possibleextreme forward position of the portion of the crosshead. Hence norelease can take place. v

The beveled nose 15 of the channelmember insures .theproper positioningof this slot to effect registration. For instance, if the actuator is inthe position shown in Fig. 3,' with c the nose 15 projecting throughslot llpwhen the actuatoi` is pushed forwardly to the position shown inFigure 1 the nose 15 will at once contact with the conical wall 2b ofthe tube 2,.thus shifting the channel member 13 rearwardly the correctdistance to reposition the slot'16 at a place where it will release th'ecrosshead when the latter reaches its releasing position, Figure ,2.

A simple arrangement for automatically shifting the channel memberforwardly in the actuatortube 8 to carry the slot 16 beyond crossheadregistering position is provided-by.. thev indent or dimple 13 in theinner wall of the channel member.

Considering once more the position ofthe pencil as shown in .Figure 1with the crosshead 17. in threaded en agement with the upper threadedzone 3 o the barrel 2, if it be desired to pull out the actuator tube 8into the position shown in Figure 3 while still maintaining thevthreaded connection between the crosshead 17 and the barrel it will benoted that as the actuator 8 is withdrawn the crosshead 17 will remainstationary relative to the-barrel 2. But the actuator, including thechannel member 13, will be drawn rearwardly past the crosshead. Duringthis shifted to a predetermined position.

diagonally extending aperture 25 is stampedl in the tube 8- and anindent 26 is formed in.

movement the dimple 13 on the side of the channel member in theactua-tor will come into contact with the crosshead 17 and the channelmember will be held slightly from further rearward movement while theactuator 8 continues lto move rearwardly. This shifts the channel member13 forwardly of the actuator 8A s o that the nose 15 of the memberpasses through the slot 11 in the shoulder 11 of the l actuator as shownin Figure v3. This is the nonregistering position of thev slot 16. Itwill be noted that the conical shoulder 11 is now withdrawn .from itsnesting shoulder .2" of the casing so that there is no abutting wall 2*'to prevent the projecting of the nose 15. Y f

This. indent 13 does not extend inwardly so far as to prevent thecrosshead passing it ly by the conical shoulder 2b when the actuator 8and crosshead 17Y are finally screwed to extreme advanced vposition asin Figure 2. A t this time the indent will permit the crosshead tofrictionally pass by, in either case the crosshead 17 .when engaging'the indent 13' will drag the channel member along with it the requiredslot positioning distance until the one end of the channel membercontacts either against the washer 27 or the opposite shoulder 14contacts'against the wall of slot 11 orl the nose 15 against the conicalshoulder Y 2. After this contact .the crosshead frictionally passes thedetent 13.

The tube 8 has'a longitudinally extending slot 22 -stamped therein atits outer end. This slot is preferably Asubstantially trian ular inshape with the a vat the outer en ofthe tube. loosely lits around tube 8and is capable of slight endwise movement on the tube as well asangularmovement thereon. This sleeve 23.has a correspondin slot 24stamped therein and of similar s ape. These slots are adapted. to beregistered when the sleeve the tube 23 toproject into. the opening 25.

This aperture 25 and detent 26 constitute a.

simple means for limiting the endwise and angular shifting of sleeve 23on the tube 8 for determining the proper opening and closing when thenose 15 is nally pushed rearwardx of the triangle isp'osed A A sleeve23v positions of the relatively shiftable slots. It

must be manifest'that by rotating the sleeve 23, the apertures 22 and 24may be ahgned to permit lead being withdrawn from the lead chamberformed in the upper portion of the Shell8. This lead channel issegregated from p thelowerpart o'f the feeding mechanism by means ofa'washer 27 which is spun in the tube directly back of the slot 10.

Due to the triangular shape of the slots22 and 24 the lead will beprojected more easily outwardly as illustrated in Figure 5. This is dueto the smallness of the slot at the apex,

a 1 ing I withdrawn which is slightly rounded and of sufiicient width topermit a single lead to proj ect therethrough, while the graduallyincreasing size of the aperture upwardly from the apex permits suchsingle lead to roll more quickly into projecting position. In otherwords the larger upper opening expedites the projection of the singlelead from the aperture.

A cap 28 is provided to slip over the member 12, thus forming a coverfor the eraser.

29, and a grip means whereby the interior mechanism may be rotated topropel thelead. The operation of the device is as follows:

A lead is inserted in the small aperture formed by the swedging of theend 9, the barrel is inserted over the feeding mechanism untilthethreads 20 of the'crosshead 17 strike thethreads in the tube 2,whereupon the feedinechanism is rotated in a clockwise direction and thecrosshead and the plunger 21 will advancev forwardly propelling the leadthrough the lead holding member 2a thru the aperture in the end of thetip to writing position. l*

A When the crosshead and the plunger have expelled practically all ofthe lead the crosshead will be in the lower end of the threaded portionof the shell 2, andin the lower end of each of `guide 13 and the tube 8.Alug 30 formed on the smooth face of the crosshead 17 drops into theaperture 16 in the tube 13, thus causing the threads on the crosshead todisengage from the threads in the tube 8. The lfeeding mechanism maythen be withdrawn from the barrel by a mere longitudinal pull and newlead may be inserted by turning the sleeve 23 and removing a new leadthrough apertures 22l and 24, and the pencil reloadedas heretoforedescribed.

Applicant wishes to particularly point out that although the feedingmechanism maybe withdrawn from the barrel when the lead has beenentirely expelled from the. pencil, that in no other position during thefeeding operation may the said feeding mechanism bq from the barrel bymeans of 1ongitudinal pull. In other words, the barrel and the pencilare attached together until all of the lead has been expelled from thepencil. The pencil and mechanismmay be freely rotated at that pointwithout injury to the mechanism.

Many departures from and variations may be/ made in the specificstructure herein shown Without departing from the spirit of myinvention, the scope of which is to be deteroperate with saidplunger-carrying member mined in the appended claims. Y

I-Iaving' described my invention, what I desire to secure by LettersPatent in the U. S. Patent Oliice is 1. A mechanical pencil comprising acasing, a lead feeding plunger, means for imparting movement to saidplunger,l and a guide member normally maintainingthe plunger inengagement with said movement imparting means, throughout themajorportion of its travel, said guidemember being constructed torelease the plunger from said engagement only at the limit of its leadfeed'- ing movement.

2.l A mechanical pencil -comprising a casing, a lead feeding unitmovable within the casing, means for causing the unit to travel withinthe casing, and a guide member normally maintaining said 'unit inengagement with its travel causing means, the major portion of itstravel, said guide member being constructed to release the unit fromsaid travel causing means only at the limit of its lead feeding travel.y

a 3. A mechanical pencil comprising a casing, parting movement to saidplunger, 'and a guide member having means constructed to hold saidplunger and its movement causing means in engagement until said plungerhas moved in one direction to a predetermined position, whereupon saidplunger may be witllidrawn from said position by a straight pul Il. Amechanical pencil comprising a casing, a lead propelling means, saidcasing and said means having complemental engaging parts by means, ofwhich said propelling means may be caused to travel, and a guide memberacting -to normally maintain engagement of the casing and leadpropelling means throughout the major portion of the travel of thelatter, and constructed to permit disengagement thereof when the leadpropelling member reaches a predetermined position.

5. In a mechanical pencil the combination of a casing having a threadedportion and a tip, a plunger carrying member, and means for normallynmaintaining engagement of said member with the threaded portion of thecasing, whereby said member may be caused to travel within the casing toadvance a. lead through said tip, said plunger carrying-member beingrcleasable from said threaded portion only when said member reaches apredetermined position in its travel. 6'. In a mechanical pencil thecombination of a casing having athreaded portion and a tip, aplungercarrying member, and means for normally maintaining engagement ofsaid member with the threaded portion of the casing, whereby said membermay be caused to travel within the casing to advance a lead through saidtip, said engagement maintaining means having a portion arranged tocosaid member with the threaded portion of the casing, whereby saidmember may be caused throughout a lead feeding plunger, means for imlmaar -andsa-id casing at a termined ing means havlnga portlon disposedin the path of travel of said plunger-carrying mem# ber to permitdisengagement of sald member predetermined position in the travel ofsaid member.

8. In a mechanical penci1,.the combination o-f a casing having athreaded portion and a tip, a plunger in-said casin having acrossheadadapted to engage sa1d threaded por-A tion and mounted forendwise and bodily latl eral Amovement relative to said casing, andmeans in said casing constructed to prevent the lateral movement of saidcrosshead until it reaches a predetermined position in its endwisemovement.

9. In a mechanical pencil, the combination of a casing having a threadedportion and a tip, a plunger in said casin having a crosshead adapted toengage said threaded portion, an actuator adapted to operate saidcrosshead to cause said crosshead and plunger to advance relative to thecasing whereby to propel the lead throughthe tip, means carried by saidactuator constructed to lock said crosshead andthreaded portionin pro'`pelling engagement, said means being movable relative to said actuatorto relea'sesaid propelling engagement.

' 10. In a y,mechanical pencil, the combinai tion of a casing'having athreaded portlon and a tip, a plunger in said casin havin a crossheadadapted .to engage said threa ed portion, a movable actuator adapted tooperate said crosshead to cause it and the lunger to advance relative tothe casing an propel the lead through the tip, means movably mounted insaid actuator for locking said crosshead and threaded portion inpropellin engagement, said means being constructed and arranged toautomatally unlock said crosshead and threaded portion at a predepoint-'in the movement of said crosshead. v

11. In a mechanical pencil, a casing, a' lead feeding plunger, meansforv imparting a feeding movement to said plunger, and a guide membercarried by -a movable portion of'the feeding means for maintaining lanormal engagement. between the plunger and thel casing, said' guidemember being con# structed to parts effecting lead feeding movement whenthe plunger reaches a predetermined position.

12. In a mechanical pencil, the combination of a casing having athreaded portion and a tip, a lunger in said casing having a` crossheada a ted to engage said threaded portion, a Inova le actuator adapted tooperate said crosshead to cause the plunger to advance relatively to thecasing whereby to propel the lead through the tip, a substantial- 1yU-shaped channel member. mounted on said actuator and adapted to receivea porrmit disengagement of the tion of saidcrosshead soas to maintainthe Y latter in propelling engagement with said 'threaded portlon, saidchannel member-having a cut-away portion disposedto permit thedisengagement of said crosshead and threaded portion.

13. In a. mechanical pencil, the combination of a casing having athreaded portion and a tip, a plunger in said casing havmg a cross-'outformed therein to permit said crossheadv to disengage from saidthreaded portion when said crosshead is in forward position, saidchannel member having va portion adapted to contact with said casing .tothereby insure the correct positioning of said cutsout opposite theforward position of said crosshead.l

14. In a mechanical ncil, the combination of a casing having a t readedportion and a tip, a plunger 1n said casing'having a -crosshead adaptedto engage 'saidthreaded portion, a movable actuator; adapted to disposethe crosshead in yextreme forward position to propel said leadsubstantially entirelyl through said tip,-a channel member movablymounted' on said actuator and adapted to receive said crosshead' so asto maintain the latter in propelling engagementwih said threadedportion, said channel member hav;

ing a cut-out formed therein to permit said crosshead to disengagefromsaid threaded portion when said crosshead is in forward position, saidchannel member having a portion adapted to contact with said casing inthe forwardposition of the crosshea/d, to thereby insure the correctpositioning of said cut-out opposite the forward position of saldcrosshead, and said memberhaving a. portion adapted to yieldably engagewith said crosshead to be shifted there y to carry said slot beyondcrosshead registering posltion.

15. In a mechanical pencil, the combinatlon of a casing having athreaded portion, a plunger operative in said casing and havn acrosshead adapted to engage said thread portion to propel the lead, anactuator in sa1 d casing adapted to propel the crosshead longitudinallyof the casing, a. guide memberadapted normally to 'cause interlockeddrivling engagement between said crosshead and threaded portion, a slotin said guide member adapted to register with said crosshead at acertain position to release said interlocked zdriving engagement, andmeans on said 'uide member cooperating with said crosshea normally toshift said guide member to prevent registration of said slot andcrosshead.

o a yieldable detent 16. In a mechanical pencil the combination of acasing having a threaded portion, a plunger operative in said casing andhaving a crosshead adapted to engage said threaded portion to propel thelead, an actuator in said casing adapted. to propel the crossheadlongitudinally of the casing, a guide member adapted normally to causeinterlocked driving engagement between said crosshead and threadedportion, a slot in said guide member adapted on predetermined relativepositions of said crosshead and guide member toregister with saidinterlocked drive ing engagement, said guide member having thereonarranged in the path of movement of said crosshead whereby to shift saidguide member on certain other relative positions of said crosshead andguide member to prevent registration of said slot and crosshead.

17. In a mechanical pencil, the combination of a casing, a leadpropelling mechanism' therein provided with driving mechanism forengaging said casing to propel the lead, a member movable with andrelative to said propelling mechanism and provided with means forreleasing said driving engagement between said casing and propellingmechanism, and means to cause said member to move relatively to saidpropelling mechanism to prevent the release of said driving engagement.

18. In a mechanical pencil, a holder2 and means associated therewith forpropelling a lead, said propelling means comprising relatively rotatableactuating and cooperating feeding means, and lmeans operable only at Aapproximately the termination of the lead propelling movement to breakthe operative connection between the lead propelling instrumentalitiesto permit withdrawal of at least a portion thereof from the holder by adirectlongitudinal pull, said last mentione means comprising alongitudinally shiftable element compelling the operative connectionduring the propelling. movement, but permitting relative recession ofsaid instrumentalities at the breaking point, and means for efecting thelongitudinal shifting of said element.

19. In a mechanical pencil, a holder, and means associated therewith forpropelling a lead, said propelling means comprisin a relativelyrotatable threaded sleeve an cooperating threaded feeding operable, onlyat tion of the lead propelling movement to break the operativeconnection between the sleeve and head to permit withdrawal of the headand immediately associated parts holder by a direct longitudinal pull,said last mentioned means comprising a longitudinally shiftable elementcompelling the operative connection during the propelling movement p butpermitting relative recession of said d the lead feed unit connecting itwith head, and means P approximately the terminafrom the `portion of itstravel, said guide being constructed to release the plunger only at thesubstantial limit of its lead feeding travel.

21. A mechanical pencil comprising a cas ing and lead feeding meansoperatively associated with the casing, a guide adapted to maintainoperative connection between said casing and lead feeding means duringfeed ing movement ofuthe latter, said guide being constructed andarranged to release the lead feeding means only at the substantial endof its lead feeding movement.

22. In a pencil a casing having a threaded part, a lead feed unittherein comprising a lead feed actuating member rotatably associatedwith the casing and a plunger having a portion coacting with the threadsof the casing for moving the plunger longitudinally of saidcasing uponrotation of said actuating member, release means associated with saidplunger, and means associated with the casing for effecting operation of-the lreleasemeans to cause release of the lead feed unit from thecasing when the plunger has substantially reached its limit of leaddischarging travel.

23. A pencil comprising a casing having a threaded part and a lead feedunit having a portion coacting with the threaded portion of the casing,release means carried by said lead feed unit, and means carried' by thecas'- ing to project into means to operate the same to cause release offrom the casing when the lead feed unit has substantially reached itslimit of lead discharging operation.

24. In a mechanical pencil the combination of a casing having a threadedportion, a feed unit removable from the casmg for loading, said unithaving means operatively the threaded rtion of the casingy during anduntil the ceding of the lead is practically completed, yand means forcausing release of said connection when the feeding'of the lead issubstantially comleted.

25. In a mechanical pencil, the combination of a easing, a lead feedunit therein and having a part to' the casing and a part adapted toengage the. casing'and be moved longitudinally of the casing by rotationof said first mentioned part, and releasing means carried by therotating part and operative to engage a art on the' casing to releaseengagement o the longitudinally movable part from v the the path of saidrelease adapted to rotate relatively 1,7aa14a movable relatively theretoand to release the longitudinally.movable part from the casing to permitWithdrawal of-'the feed unit from the casing upon a straightlongitudinal pull.

27. In a mechanical pencil, the combinaytion of a casing, a lead feedunit therein and having a, rotary vpart and a longitudinally movablepart adapted'to engage the casing, and means carried by the: rotaay partand movable relatively .thereto'bycontact with A .a part of the casingfor "automatically re-r leasing the feed unit. from the easing.'v

28. In a mechanical pencil, thecombination of a casing having a threadedpart, a lead feed `unit therein adaptedto rotate relative to the casing,a lead propelling member carried by said unitand having athreaded partengaging the threaded portion ofthe'. casing, v for causing the leadpropelling member tobe advanced by the rotation of said unit, a

device carried by the lead feed unit adapted to engage the leadpropelling member to maintain its engagement with the threaded portionof the casing during certain portions of the travel of the threaded partof the -proellino member said device beinor constructed and arranged tocause the automatic disengagement of said threaded parts vat a definitepoint of the travel of the threaded part of the propelling member andmeans for prel venting the automatic disengagement of said threadedparts at any other oint in the travel of said threaded part o thepropelling member. 'Y l 29. In a mechanical pencil, the combina-I tionof a casing having a thread, a lead feed unit therein comprising anactuator rotatably engaging the casing and carrying a cross-v headadapted to engage the lthread of the casing for feeding the leadlthrough the casing on rotation vof the actuator, an automatic releaseshiftably carried on the actuator and engaging the crosshead to maintainit in engagement with the thread of the casing, said release having aportionv arranged to cause the disengagement of the crosshead from thecasing thread at a definite point in its travel, said release having aportionadapted to be engaged by the casing to shift the automaticrelease in one direction and having another portion adapted to beengaged by the crosshead to shift the automatic release in the oppositedirection.

30.l In a mechanical pencil, the combination of a casing vhaving athread, a lead feed unit therein having a rotary part and a translatablecross-head adapted to engage the thread of the casing, and an automaticreleasing device for the crosshead having a resilient part adapted to beengaged by the crosshead to cause movement of the device, said resilientpart permitting the crosshead to move past the resilient part in itsoperative travel.

31. In a mechanical pencil, the combination of acasing having a thread,a lead feed unit therein having a rotary part and a translatablecrosshead adapted to engage the thread of the casing, and achannel-shaped' sheetlmetal guide having a slot near one end, a noseadjacent thereto and an indent adjacent the s/lot, said slot permittingthe crbsshead to pass thereinto to release from the casing thread, saidnose being adapted to projectthrough an aperature in the rotary part ofthe feed unit to be contacted by the casing to shift the guide in 'onedirection and said indent being adapted to be contacted by the crossheadto cause the shifting of the guide in another direction, said indentbeing resilient to permit the passage of the crosshead.

32. In a pencil thecombination of a threaded casing, a lead feedunit'associated therewith comprising an actuator rotatably mounted insaid casing, a cross-h ead movable in said actuator between two extremeposltlons and engaglng the threads of the easmg, a guide adapted to movein the actuator between two extreme positions and relative to thecross-v head, said uide having a slot adapted to register wit thecross-head only when the actuator and cross-head are in extreme forwardposition at the front portion of the casing and means to prevent theslot in the guide registering with the cross-head in any otherlpositions of the actuator, cross-head and guide. Y

In witness whereof I have hereunto subscribed my name.

. JOHN C. WAHL.

